Nut (fruit)

A nut is a fruit composed of an inedible hard shell and a seed, which is generally edible. In general usage, a wide variety of dried seeds are called nuts, but in a botanical context "nut" implies that the shell does not open to release the seed (indehiscent). The translation of "nut" in certain languages frequently requires paraphrases, as the word is ambiguous.

Nuts market
Nuts being sold in a market

Most seeds come from fruits that naturally free themselves from the shell, unlike nuts such as hazelnuts, chestnuts, and acorns, which have hard shell walls and originate from a compound ovary. The general and original usage of the term is less restrictive, and many nuts (in the culinary sense), such as almonds, pecans, pistachios, walnuts, and Brazil nuts,[1] are not nuts in a botanical sense. Common usage of the term often refers to any hard-walled, edible kernel as a nut.[2] Nuts are an energy-dense and nutrient-rich food source.[3]

Chestnut
Chestnuts are both botanical and culinary nuts.
Common-nuts
Some common "culinary nuts", including hazelnuts (which are also botanical nuts), Brazil nuts (which are not botanical nuts, but rather seeds of a capsule), walnuts, pecans, and almonds (all three of which are not botanical nuts but rather the seeds of drupes).

Botanical definition

A nut in botany is a simple dry fruit in which the ovary wall becomes increasingly hard as it matures, and where the seed remains unattached or free within the ovary wall. Most nuts come from the pistils with inferior ovaries (see flower) and all are indehiscent (not opening at maturity). True nuts are produced, for example, by some plant families of the order Fagales.

Order Fagales (not all species produce true nuts)

A small nut may be called a "nutlet". In botany, this term specifically refers to a pyrena or pyrene, which is a seed covered by a stony layer, such as the kernel of a drupe. Walnuts and hickories (Juglandaceae) have fruits that are difficult to classify. They are considered to be nuts under some definitions, but are also referred to as drupaceous nuts. "Tryma" is a specialized term for hickory fruits.

In common use, a "tree nut" is, as the name implies, any nut coming from a tree. This most often comes up regarding allergies, where some people are allergic specifically to peanuts (which are not tree nuts), others to a wider range of nuts that grow in trees.

Culinary definition and uses

W Nuss Gr 99
A walnut, left, and its seed, right, having been removed from its pericarp
KoreanPineSeeds
Seeds of the Korean pine in shell and empty shell, above; removed from shell, below

A nut in cuisine is a much less restrictive and older meaning of the word than the narrow meaning of nut in botany; the term is applied to many seeds that are not botanically nuts. Any large, oily kernels found within a shell and used in food are commonly called nuts.

Nuts are an important source of nutrients for both humans and wildlife.[3] Because nuts generally have a high oil content, they are a highly prized food and energy source. A large number of seeds are edible by humans and used in cooking, eaten raw, sprouted, or roasted as a snack food, or pressed for oil that is used in cookery and cosmetics.[3]

Nuts used for food, whether true nut or not, are among the most common food allergens.[3][4]

Fancy raw mixed nuts macro
Raw mixed nuts, sold as a snack food. This is a "fancy" mix, meaning that it does not include peanuts.

Some fruits and seeds that do not meet the botanical definition but are nuts in the culinary sense are:[3]

Nutrition

Constituents

Nuts are the source of energy and nutrients for the new plant. They contain a relatively large quantity of calories, essential unsaturated and monounsaturated fats including linoleic acid and linolenic acid, vitamins, and essential amino acids.[3] Many nuts are good sources of vitamin E, vitamin B2, folate, fiber, and the essential minerals magnesium, phosphorus, potassium, copper, and selenium.[3][6] Nuts are most healthy in their raw unroasted form because roasting can significantly damage and destroy fats during the process.[7]

Nuts and seeds (996x563)
A graph detailing the nutritional properties of nuts and oily seeds.

This table lists the percentage of various nutrients in four unroasted seeds.

Name Protein Total fat Saturated fat Polyunsaturated fat Monounsaturated fat Carbohydrate
Almonds 21.26 50.64 3.881 12.214 32.155 28.1
Walnuts 15.23 65.21 6.126 47.174 8.933 19.56
Peanuts 23.68 49.66 6.893 15.694 24.64 26.66
Pistachio 20.61 44.44 5.44 13.455 23.319 34.95

Research

Nuts are under preliminary research to assess whether their consumption may lower risk for some diseases, such as cardiovascular diseases and cancer.[3][8][9]

Nuts have a low glycemic index (GI)[10] due to their high unsaturated fat and protein content and relatively low carbohydrate content.

Other uses

The nut of the horse-chestnut tree (Aesculus species, especially Aesculus hippocastanum), is called a conker in the British Isles. Conkers are inedible to humans and many animals because they contain toxic glucoside aesculin. They are used in a popular children's game, known as conkers, where the nuts are threaded onto a strong cord and then each contestant attempts to break their opponent's conker by hitting it with their own. Horse chestnuts are also popular slingshot ammunition.

See also

References

  1. ^ Alasalvar, Cesarettin; Shahidi, Fereidoon. Tree Nuts: Composition, Phytochemicals, and Health Effects (Nutraceutical Science and Technology). CRC. p. 143. ISBN 978-0-8493-3735-2.
  2. ^ Black, Michael H.; Halmer, Peter (2006). The encyclopedia of seeds: science, technology and uses. Wallingford, UK: CABI. p. 228. ISBN 978-0-85199-723-0.
  3. ^ a b c d e f g h "Nuts". Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis, OR. 1 September 2018. Retrieved 28 March 2019.
  4. ^ "Common Food Allergens". Food Allergy & Anaphylaxis Network. Archived from the original on 2007-06-13. Retrieved 2007-06-24.
  5. ^ Lina Sequeira. Certificate Biology 3. East African Publishers. pp. 130–. ISBN 978-9966-25-331-6. Retrieved 29 July 2010.
  6. ^ Kris-Etherton PM, Yu-Poth S, Sabaté J, Ratcliffe HE, Zhao G, Etherton TD (1999). "Nuts and their bioactive constituents: effects on serum lipids and other factors that affect disease risk". Am J Clin Nutr. 70 (3 Suppl): 504S–511S. doi:10.1093/ajcn/70.3.504s. PMID 10479223.
  7. ^ "The Difference Between Raw, Pasteurized and Roasted Almonds". Legendary Foods. Archived from the original on 2016-10-06.
  8. ^ Aune, D; Keum, N; Giovannucci, E; Fadnes, LT; Boffetta, P; Greenwood, DC; Tonstad, S; Vatten, LJ; Riboli, E; Norat, T (5 December 2016). "Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies". BMC Medicine. 14 (1): 207. doi:10.1186/s12916-016-0730-3. PMC 5137221. PMID 27916000.
  9. ^ Luo, C; Zhang, Y; Ding, Y; Shan, Z; Chen, S; Yu, M; Hu, FB; Liu, L (July 2014). "Nut consumption and risk of type 2 diabetes, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis". The American Journal of Clinical Nutrition. 100 (1): 256–69. doi:10.3945/ajcn.113.076109. PMID 24847854.
  10. ^ David Mendosa (2002). "Revised International Table of Glycemic Index (GI) and Glycemic Load (GL) Values". Retrieved 2007-11-23.

Further references

  • Albala, Ken 2014. Nuts A Global History. The Edible Series. ISBN 978-1-78023-282-9
Brazil nut

The Brazil nut (Bertholletia excelsa) is a South American tree in the family Lecythidaceae, and also the name of the tree's commercially harvested edible seeds.

Cydia (moth)

Cydia is a large genus of tortrix moths, belonging to the tribe Grapholitini of subfamily Olethreutinae. Its distinctness from and delimitation versus the tribe's type genus Grapholita requires further study.Moths in this genus are generally small and dull brown; their caterpillars are yellow or white and wormlike. Cydia includes many species of economic importance due to the damage their caterpillars inflict as pests of agricultural crops, especially fruit and nut trees. On the other hand, some Cydia species have been used for biological control of invasive weeds, and many of these small moths and their caterpillars are an important food source for other animals. A few species from the Hawaiian Islands are suspected to be extinct due to disappearance of their food plants.

Another well-known species is the jumping bean moth (C. deshaisiana), whose caterpillars live in Sebastiania seeds, turning them into the famous "Mexican jumping beans".

Cydia kurokoi

Cydia kurokoi, the nut fruit tortrix, is a moth of the family Tortricidae. It is found in Japan, the Korean Peninsula and eastern China.

The wingspan is about 20 mm. Adults are on wing in August and September. There is one generation per year.

The larvae feed on Castanea seguinii, Castanea mollitissima, Castanea crenata and Quercus acutissima. The larvae feed inside the fruits of chestnut trees and damage them.

M

M (named em ) is the thirteenth letter of the modern English alphabet and the ISO basic Latin alphabet.

Outline of sustainable agriculture

The following outline is provided as an overview of and topical guide to sustainable agriculture:

Sustainable agriculture – applied science that integrates three main goals, environmental health, economic profitability, and social and economic equity. These goals have been defined by a variety of philosophies, policies and practices, from the vision of farmers and consumers. Perspectives and approaches are very diverse, the following topics intend to help understanding what sustainable agriculture is.

Pome

In botany, a pome (derived from Latin pōmum, meaning "fruit") is a type of fruit produced by flowering plants in the subtribe Malinae of the family Rosaceae.

Victory garden

Victory gardens, also called war gardens or food gardens for defense, were vegetable, fruit, and herb gardens planted at private residences and public parks in the United States, United Kingdom, Canada, Australia and Germany during World War I and World War II. George Washington Carver wrote an agricultural tract and promoted the idea of what he called a "Victory Garden". They were used along with Rationing Stamps and Cards to reduce pressure on the public food supply. Besides indirectly aiding the war effort, these gardens were also considered a civil "morale booster" in that gardeners could feel empowered by their contribution of labor and rewarded by the produce grown. This made victory gardens a part of daily life on the home front.

Types of fruits
Types of fruits
Categories of fruits
Function
Nuts
True, or botanical nuts
Drupes
Gymnosperms
Angiosperms
Animal products
Edible plants / roots
Mushrooms
Resins
Sap / Gum / etc.
Other
Related

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